In the framework of human space flight, the active control of temperature inside crewed modules assumes a paramount importance in protecting the habitable environment from the harsh thermal conditions of the outer space. This study, carried out in collaboration with Thales Alenia Space Italia, concerns the conceptual design of a Compact Heat Exchanger (CHX), for space applications, to be used with two streams of 3M Novec HFE 7200 DL in the temperature range from -50 to 6.5 °C. The proposed design considers a Triply Periodic Minimal Surfaces (TPMS) Heat Exchanger in stainless steel based on prismatic gyroids, obtained filling homogenously all the available volume allocated for the component.